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Updated: Sep 21, 2026

Examination of Proteins Bound to Nascent DNA in Mammalian Cells Using BrdU-ChIP-Slot-Western Technique
09:14

Examination of Proteins Bound to Nascent DNA in Mammalian Cells Using BrdU-ChIP-Slot-Western Technique

Published on: January 14, 2016

Neocarzinostatin-induced breakdown of deoxyribonucleic acid in HeLa-S3 cells

K Ohtsuki, N Ishida

    The Journal of Antibiotics
    |February 1, 1975
    PubMed

    Insights

    Neocarzinostatin (NCS) causes DNA damage in HeLa-S3 cells, initiating single-strand nicks and later double-strand breaks. Early-stage DNA damage from NCS is repairable when cells are moved to a drug-free environment.

    Area of Science:

    • Molecular Biology
    • Biochemistry
    • Cell Biology

    Background:

    • Neocarzinostatin (NCS) is an acidic antitumor protein with known effects on DNA.
    • Understanding the precise mechanisms of NCS-induced DNA damage is crucial for cancer therapy development.

    Purpose of the Study:

    • To investigate the DNA degradation process in HeLa-S3 cells induced by neocarzinostatin (NCS).
    • To characterize the types of DNA damage and the reversibility of these effects.

    Main Methods:

    • Utilized HeLa-S3 cells for experimental analysis.
    • Employed sedimentation analysis to examine DNA integrity after NCS exposure.
    • Assessed DNA repair mechanisms by transferring treated cells to NCS-free medium.

    Main Results:

    • NCS induced DNA degradation in HeLa-S3 cells, with higher concentrations required for degradation than for DNA synthesis inhibition.
    • Single-strand DNA nicks were observed within 60 minutes of NCS exposure.
    • Double-strand scissions occurred later, leading to DNA fragments of varying sizes.
    • Early-stage single-strand nicks were repairable in a puromycin-sensitive manner upon removal of NCS.

    Conclusions:

    • Neocarzinostatin (NCS) induces sequential DNA damage, starting with single-strand nicks and progressing to double-strand breaks.
    • The DNA damage caused by NCS is partially reversible, particularly the initial single-strand nicks, suggesting active cellular repair pathways.
    • These findings provide insights into the DNA-damaging mechanisms of NCS and potential therapeutic strategies.

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